Impact of pregnancy and oestrogen on psoriasis and potential therapeutic use of selective oestrogen receptor modulators for psoriasis

Majority of female patients show improvement of psoriasis during pregnancy. This is demonstrated to be correlated with high levels of oestrogen. Even in male patient, oestrogen level is inversely correlated with the severity of psoriasis. However, a minority of female psoriatic patients still experience worsening during pregnancy. Oestrogen might improve psoriasis by suppressing the T-cell immune response, reducing the keratinocyte (KC) cytokine and chemokine production, restoring the balance of redox and enhancing the skin barrier. However, it might worsen the disease by stimulating KC proliferation and promoting angiogenesis. This complex role of oestrogen in the pathogenesis of psoriasis might explain why the two opposite effects of pregnancy coexist. Data shows that the number of improving patients with psoriasis in pregnancy is double the number of the worsening patients, suggesting that oestrogen may be potentially useful in the treatment of psoriasis. However, oestrogen is not considered suitable as a long-term treatment subject to negative side-effects. This review discusses current studies on taking selective oestrogen receptor mediators as a novel potential therapeutic option for psoriasis.